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2-4 Solutiona.fcMHzfIF= 500kHz(down-conversion)fIF= 60MHz(up-conversion)fLO(MHz)fIM(MHz)fLO(MHz)fIM(MHz)10.51.502.0615912111955.54.56.04.065551251151515.514.5161475451351052525.524.526248535145953030.529.53129903015090b.fLO(MHz)Tuning ratioR=fLO,max/fLO,min1.5–30.520.30.5-29.55961-901.47559-301.967c. From the standpoint of easiest and least expensive preselector and LO design, the optimum configurationis up-conversion with high-LO (fLOtunes over the range 61-90 MHz). This configuration has the smallesttuning ratio (R= 1.475)and all image responses are located well above 30 MHz, which is the upper-cutofffrequency of the carrier-frequency band of interest. Hence, the preselector can consist of a fix-tuned lowpassfilter with cutofffrequency at 30 MHz.The preselector response should be as small as possible over therange 121-150 MHz in order to provide maximum possible rejection of image responses.1
2-8 Solutiona. 58.6, 80, 278.6, 300, 2520, 2541.4, 2878.6, 2900 MHzb. There would 16 frequencies on the list if there were 4 conversions instead of 3.